Volvo ECC concept: this is how Volvo saw hybrids 20 years ago, with an electric motor and a diesel turbine

Saying that the future of Volvo began 20 years ago, when the Swedish brand presented its Volvo ECC, would not be far-fetched. Its name comes from the initials of Enviromental Concept Car, which we could translate as “environmental concept car”, or something similar. Volvo’s idea was to propose a vehicle capable of offering the best of two worlds: electric propulsion to reduce pollution in large cities, and the advantages of a diesel engine in terms of low consumption and range when travelling on the road. You’re sure to have heard of it… But mind you, we’re talking about 1992. To put it in context, the first mass-produced hybrid car, the Toyota Prius, did not reach the market until 1997.

The fact is that Volvo took advantage of this rolling laboratory to also showcase the revolutionary lines its future models would have, anticipating the design language that debuted six years later on the Volvo S80, and which continued to be used for years in many other models from the brand. The prototype also introduced solutions that are now completely standard, such as its construction with lightweight materials of low environmental impact and a high recycling rate (thanks to its aluminium body the weight was kept at 1,580 kg), or the “Dynaguide“, an innovative system at the time that gave the driver up-to-date real-time traffic information on the instrument cluster.

But that is another story. What concerns us today, and why we have recovered this unique prototype, is what a hybrid concept meant at that time. And even more so a hybrid like this one.

An electric motor and a gas turbine fuelled by diesel

Let us go back to the early 1990s, when it was announced that, from 1998, California legislation would require car manufacturers to ensure that at least 10% of their sales in this State corresponded to zero-emission vehicles, which spurred brands to dedicate themselves to researching how to put genuinely usable electric cars on the market. It was not a measure that affected Volvo, with a sales volume that allowed the Swedish brand to be exempt from it. But at Volvo they were already looking to the future… In fact, in 2011 Volvo became the first brand to market a plug-in hybrid with a diesel engine, the Volvo V60 Plug-In Hybrid.

However, the hybrid solution proposed by the Volvo CC never caught on. Under its bonnet, instead of a conventional diesel engine there was a very compact gas turbine developed by United Turbine, a subsidiary of Volvo’s aviation engine company. Fuelled by diesel, the turbine drove a 40 kW electric generator to produce the electricity that would power the 70 kW (95 CV) electric motor responsible for driving the front wheels through a two-speed gearbox.

Ahead of its time

The heavy batteries for their energy density (around 350 kg), still nickel-cadmium, were distributed under the boot and the central tunnel. The fact that they could be recharged by plugging them in for a full night, or on the move using the surplus energy from the turbine itself or through regenerative braking, shows that Volvo had a very clear idea of how a hybrid car should work. The saloon, which already boasted a drag coefficient Cx of just 0.23, could reach a top speed of 175 km/h. With so little power, acceleration was nothing to write home about: 12.5 seconds to accelerate from 0 to 100 km/h is today considered the figure of a “slow” car. But it showed promise, with an electric-mode range of 80 km, and a total range of 650 km, thanks to the 35-litre diesel tank.

Despite being a technologically very advanced car, the driving proposition was simple. An electric mode, a hybrid mode and a turbine mode. In hybrid mode, the system took care of activating the turbine if the driver demanded a lot of power, or when battery capacity fell below 20 per cent.

However, the future commercialisation of a hybrid like this one would depend on two factors: the advances in battery technology, which came very quickly… and the low production volume of small turbines, which made the cost very high. Hence, ultimately, the aforementioned Volvo V60 Plug-In Hybrid was also a plug-in hybrid with a diesel engine… but with a conventional combustion engine.

Volvo ECC Concept – Image gallery